Gear with flexible crownwheel



April 24, 1962 r E. PARODI 3,030,894

GEAR WITH FLEXIBLE CROWNWHEEL Filed July 22, 1957 t INV ENTOR. [/1 0 7 a raaz.

@M KMQ M United States Patent Ofiilce 3,030,894 Patented Apr. 24, 1962 3,030,894 GEAR WITH FLEXIBLE (IROWNWHEEL Elio Parodi, Rua Sao Juliao 802, Lisbon, Portugal Filed July 22, 1957, Ser. No. 673,501 Claims priority, application Portugal July 21, 1956 2 Claims. (Cl. 103126) The present invention relates to a new assembly of gears which may be used as a liquid or a gas pump or as a hydraulic coupling. An object of the invention is to provide a construction involving a rotating gear which engages tangentially with a flexible internally toothed crown wheel or a chain.

A further object of the invention is to provide a casing wherein the gears are enclosed having inlets and outlets at diametrically opposed points.

A still further object of the invention is to provide a construction wherein the inlets of the casing are in communication with those sectors of the gear in which the teeth of the crown wheel leave the gear and the outlets are in communication with those sectors in which the teeth of the gear approach the crown wheel.

With the above and other objects in view which will become apparent from the detailed description below one form of the invention is shown in the drawings in which:

FIGURE 1 is a side elevational view with parts shown in cross-section and FIGURE 2 is a front view with the inlet chamber removed so as to disclose the cooperating gears in elevational view.

In the drawings the gear 1 engages with a flexible crown wheel 2 at the points A and B. The direction of rotation is indicated by the arrow C in FIGURE 2 and the gear 1 is driven by the shaft 3 by any desired prime mover.

As shown in FIGURE 2 the inlets 4 and 4 are in com munication with the inlet chamber 5 shown in FIGURE 1. The outlets 6 and 6' are in communication with the outlet chamber 7. The ports for leading to the inlet chamber 5 and the outlet chamber 7 are shown in FIG- URE 1.

The casing 8 encloses the gear 1 and the crown wheel 2 and such casing has an oval shaped internal surface accommodating the oval shaped crown wheel 2. The cover 9 containing the inlet chamber 5 and the cover 10 containing the outlet chamber are located at the sides of the casing 8.

At the points D and E, see FIGURE 2, the teeth of the crown wheel 2 and the gear wheel 1 are not engaged but are opposed to one another. The crown wheel 2 is provided with one tooth more than the gear 1. At the point D the inlet 4 as shown in FIGURE 2 is separated from the outlet 6' and at the point E the inlet 4' is separated from the outlet 6.

At the point A the outlet 6 is separated from the inlet 4 and at the point B the outlet 6 is separated from the inlet 4 by the meshing of the teeth.

When the gear 1 and the flexible crown wheel 2 rotate in the direction indicated by the arrow C, fluid is sucked from the inlet chamber 5 through the inlets 4 and 4 and expelled through the outlets 6 and 6' into the outlet chamber 7.

The entire outer periphery of the crown wheel 2 contacts the oval inner surface of the casing. It will also be noted that the teeth in the gear and crown wheel are in full mesh at' diametrically opposite sides of the gear 1 on the minor axis of the oval shaped inner surface of the casing 8. Also the teeth are in open mesh at diametrically opposite sides of gear 1 on the major axis of such oval. The outlet openings 6 and 6' are sealed from the inlet openings 4 and 4' at open mesh by the sealing contact of the teeth of the gear 1 and the crown wheel 2 with each other. This does not require any sealing member in between and at open mesh the land between the inlet and outlet ports extends circumferentially more than the pitch of the teeth of the crown wheel 2.

I claim:

1. A device of the type described comprising a casing with an oval shaped inner surface having an inlet chamber at one axial side thereof, an outlet chamber in said casing at the opposite axial side thereof spaced from said inlet chamber, a gear chamber located between said inlet and outlet chambers, inlet ports in a side wall of said inlet chamber adjacent said gear chamber interconnecting said inlet chamber and said gear chamber, outlet ports in a side wall of said outlet chamber adjacent said gear chamber having substantially a cross sectional area equal to said inlet ports interconnecting said outlet chamber and said gear chamber, a single circular gear located in said gear chamber, means for rotating said gear, a flexible non-circular crownwheel having its outer periphery in contact with said oval shaped inner surface of said casing having internal teeth of a greater number than the teeth on said gear in said casing cooperating with said gear, said oval surface deforming said crownwheel so that it always has the shape of said oval surface as it rotates about the center of the oval, said gear engaging tangentially with said crownwheel at a plurality of diametrically opposite points thereby forming pressure and suction compartments between said gear and said crownwheel which expand and contract between said diametrically opposite points, the teeth of said gear and crownwheel being in full mesh at diametrically opposite sides on the minor axis of said oval, and the teeth of said gear and crown gear being in open mesh at diametrically opposite sides on the major axis of said oval; said inlets and outlets being in the side walls of said casing and sealed from each other at open mesh by lands between said ports extending circumferentially more than the pitch of the teeth of said crown gear and each outlet is sealed from the inlet at open mesh of the teeth by the sealing contact of the teeth with each other to provide a pumping chamber on each side of said minor axis in which the pockets between the teeth of said gear and crownwheel expand from a minimum volume at the inlet to a maximum volume at open mesh and contract to a minimum volume at the outlet as said gear and crownwheel rotate.

2. A device as set forth in claim 1 wherein said crownwheel is a flexible chain.

References Cited in the file of this patent UNITED STATES PATENTS 98,482 Foster Jan. 4, 1870 423,298 Winton Mar. 11, 1890 863,781 Callan Aug. 20, 1907 1,739,139 Haight Dec. 10, 1929 1,926,692 Tarbox Sept. 12, 1933 2,124,377 Schirmer July 19, 1938 (Other references on following page) 3 UNITED STATES PATENTS Linderman Aug. 9, 1938 Schmitz Apr. 29, 1941 Sibley July 28, 1942 Melville Nov. 10, 1942 Barker Oct. 19, 1948 Bunte Jan. 11, 1949 Witchger July 4, 1950 Mosbacher May 15, 1956 Rand Sept. 25, 1956 Eames May 21, 1957 Patin Feb. 3, 1959 Musser Sept. 29, 1959 FOREIGN PATENTS France Mar. 27, 1923 

